fuse: add list of writable files to fuse_inode
Each WRITE request must carry a valid file descriptor. When a page is written
back from a memory mapping, the file through which the page was dirtied is not
available, so a new mechananism is needed to find a suitable file in
->writepage(s).
A list of fuse_files is added to fuse_inode. The file is removed from the
list in fuse_release().
This patch is in preparation for writable mmap support.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 471ea70..c4c59c7 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -56,6 +56,7 @@
kfree(ff);
ff = NULL;
}
+ INIT_LIST_HEAD(&ff->write_entry);
atomic_set(&ff->count, 0);
}
return ff;
@@ -150,12 +151,18 @@
{
struct fuse_file *ff = file->private_data;
if (ff) {
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
fuse_release_fill(ff, get_node_id(inode), file->f_flags,
isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
/* Hold vfsmount and dentry until release is finished */
ff->reserved_req->vfsmount = mntget(file->f_path.mnt);
ff->reserved_req->dentry = dget(file->f_path.dentry);
+
+ spin_lock(&fc->lock);
+ list_del(&ff->write_entry);
+ spin_unlock(&fc->lock);
/*
* Normally this will send the RELEASE request,
* however if some asynchronous READ or WRITE requests
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index b24fc9b..5657cca 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -70,6 +70,9 @@
/** Version of last attribute change */
u64 attr_version;
+
+ /** Files usable in writepage. Protected by fc->lock */
+ struct list_head write_files;
};
/** FUSE specific file data */
@@ -82,6 +85,9 @@
/** Refcount */
atomic_t count;
+
+ /** Entry on inode's write_files list */
+ struct list_head write_entry;
};
/** One input argument of a request */
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 3c13981..49d7160 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -56,6 +56,7 @@
fi->i_time = 0;
fi->nodeid = 0;
fi->nlookup = 0;
+ INIT_LIST_HEAD(&fi->write_files);
fi->forget_req = fuse_request_alloc();
if (!fi->forget_req) {
kmem_cache_free(fuse_inode_cachep, inode);
@@ -68,6 +69,7 @@
static void fuse_destroy_inode(struct inode *inode)
{
struct fuse_inode *fi = get_fuse_inode(inode);
+ BUG_ON(!list_empty(&fi->write_files));
if (fi->forget_req)
fuse_request_free(fi->forget_req);
kmem_cache_free(fuse_inode_cachep, inode);